Environment and Breast Cancer: Science Review

Evidence From Humans
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Human exposure to polyhalogenated hydrocarbons and incidence of selected malignancies -central European experience
Bencko, V., Rames, J., Ondrusova, M., Plesko, I., Jurickova, L., Trnovec, T. Neoplasma. 2009. 56:4, 353-7.
Topic area
Environmental pollutant - PCBs
Study design
Funding agency
5th & 6th FP of the European Commission League Aga
Study Participants
Menopausal Status
The menopausal status of women included in this study is listed here.
No analysis based on menopausal status
Country where study was conducted
Czech Republic Slovak Republic
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
This ecologic study compared breast cancer incidence in contaminated Michalovce District compared to incidence in the Slovak Republic from 1987-1996 from National Cancer Registry of Slovak Republic. And breast cancer incidence in contaminated Uherske Hradiste in the Czech Republic compared to incidence in the Czech Republic from 1987-1996.
Exposure Investigated
Exposures investigated
The Michalovce District in Eastern Slovakia was exposed to elevated PCB levels from 1959 to 1983 because of a local chemical plant, which authors report as one of the most heavily PCB-contaminated areas of the world. Residence in the Michalovce District w
How exposure was measured
Geographic location
Exposure assessment comment
This study looks at a unique population that may have been highly exposed to PCBs. Because the range of exposures within the Michalovce District may vary geographically, the use of biomarkers of PCB exposure could inform the exposure measure used to evaluate breast cancer incidence in this population. The lack of personal exposure and risk factor information allows for the possibility of the ecological fallacy.
Breast cancer outcome investigated
Primary incident breast cancer
Confounders considered
Other breast cancer risk factors, such as family history, age at first birth, and hormone replacement therapy use, that were taken into account in the study.
Genetic characterization included
If the study analyzed relationships between environmental factors and inherited genetic variations, this field will be marked “Yes.” “No”, if not.
Strength of associations reported
Age-adjusted world standard ratio (WSR) female breast cancer incidence:
Michalovce district (Slovak Republic): IRR=0.85, p=0.01

Uherske Hradiste region (Czech Republic): IRR=0.91, p=0.20
Author address
Institute of Hygiene & Epidemiology, First Faculty of Medicine, Charles University in Prague & General University Hospital, Prague, Czech Republic. vladimir.bencko@lf1.cuni.cz
Reviewers Comments
The authors acknowledge that PCBs may induce a range of effects, including estrogenic, anti-estrogenic, and androgenic effects. The lack of individual-level information in an ecologic study design limits interpretation of associations.